You are actually able to transmit a greyscale GIF with 10fps over audible frequency ranges in real time!? I saw that horse-riding-video being transmitted and it was well recognizable on the receiver.

How much of audio bandwidth do you need for it to work? Since an external transmission (speaker to microphone) is possible, how much of that audio-signal has to remain transparent to make this work? If there is no phase rotation, maybe the information is not even sensible to lossy audio compression!